Fixed usability issues

* Fixed bug with automatic creation of the directory for repo
* Added requirements
* Updated README with installation instructions

Change-Id: Iac9c08d4fdf1113858a685f7413560325abdefbb

README.md

@@ -1,2 +1,39 @@
-# fuel-external-git
+# Nailgun API Extension with External Git Server
+### About
 Nailgun extension that generates deployment data based on configuration files published in external git repository
+### Requirements
+Deployed Fuel 9.0 (Mitaka) Master Node
+
+### Installation
+Execute following commands on Fuel Master node
+```
+# git clone https://github.com/dukov/fuel-external-git
+# cd fuel-external-git
+# pip install -r requirements.txt
+# python setup.py install
+# nailgun_syncdb
+# service nailgun reload
+```
+
+### API
+* GET /clusters/git-repos 
+  * Returns list of configured git repos for all clusters/environments 
+  * Example ```curl -H "X-Auth-Token: $(fuel token)" http://localhost:8000/api/v1/clusters/git-repos```
+* POST /clusters/git-repos
+  * Create new repo for particular cluster
+  * input data schema:   
+    ```"$schema": "http://json-schema.org/draft-04/schema#",
+           "title": "Cluster",
+           "description": "Serialized Cluster object",
+           "type": "object",
+           "properties": {
+               "id": {"type": "number"},
+               "repo_name": {"type": "string"},
+               "env_id": {"type": "number"},
+               "git_url": {"type": "string"},
+               "ref": {"type": "string"},
+               "user_key": {"type": "string"}```
+   * Example ```curl -X POST -H "X-Auth-Token: $(fuel token)" http://localhost:8000/api/v1/clusters/git-repos -d '{"user_key": "", "git_url": "https://github.com/dukov/openstack-configs", "env_id": 5, "ref": "master", "repo_name": "osconf1"}'```
+* PUT /clusters/(?P<cluster_id>\d+)/git-repos/(?P<obj_id>\d+)
+  * Updates repo with obj_id info for cluster cluster_id
+  * Example: ```curl -X PUT -H 'X-Auth-Token: $(fuel token)' http://localhost:8000/api/v1/clusters/4/git-repos/2 -d '{"ref": "master"}'```

fuel_external_git/extension.py

@@ -1,4 +1,5 @@
 import os
+import yaml
 
 from nailgun.logger import logger
 
@@ -33,6 +34,19 @@ class OpenStackConfigPipeline(BasePipeline):
         GitRepo.checkout(repo)
         repo_path = os.path.join(const.REPOS_DIR, repo.repo_name)
 
+        # Read config for overrides
+        # TODO(dukov) We need to ba able to differentiate configs.
+        # Overrides file should contain following mapping
+        #  - role:config_file
+        #  - node_id:config_file
+        # Config options from files for roles should override global
+        # configs (placed in repo root).
+        # Config options from files for nodes should override global
+        # and roles config oprions
+        overrides_file = os.path.join(repo_path, 'overrides.yaml')
+        if os.path.exists(overrides_file):
+            overrides = yaml.load(open(overrides_file))
+
         config_files = [conf for conf in os.listdir(repo_path)
                         if conf.endswith('conf')]
 

fuel_external_git/objects.py

@@ -40,6 +40,8 @@ class GitRepo(NailgunObject):
     
     @classmethod
     def create(self, data):
+        if not os.path.exists(const.REPOS_DIR):
+            os.mkdir(const.REPOS_DIR)
         repo_path = os.path.join(const.REPOS_DIR, data['repo_name'])
         if os.path.exists(repo_path):
             shutil.rmtree(repo_path)

requirements.txt

@@ -0,0 +1 @@
+GitPython==2.0.8